Jiralhanae (Brutes) are the most members of the Covenant and are large, bipedal, giant ape-like species from their homeworld: Doisac. The Brutes were the second Covenant species encountered by the humans following the Kig-Yar raid on the freighter: This End Up. The Brutes have an extreme hatred over the Sangheili, fueled by the Brute's natural aggressive nature and the Sangheili's attitudes of superiority.
The Brutes have been part of the Covenant since before the destruction of the UNSC agricultural colony on Harvest, and were always feared by the Sangheili for their monomanical behavior. The Brute's plans to seize power over the Sangheili began with their alliance with the High Prophet of Truth during the Battle of Harvest, and continued to gain headway until the eventual splitting of the Covenant Empire. They eventually took the role of the Prophet's Honor Guards from the Sangheili after they failed to prevent the assassination of the High Prophet of Regret by SPARTAN John 117. Regret's assassination culminated in the Brutes replacing the Sangheili as the leaders of the Covenant Military.